Installing your own fence can obviously save you money on the cost of a fence contractor, but tackling this job yourself can be more costly if you don't manage it properly, as you may then wind up paying for otherwise unnecessary fence repairs down the road. If you do want to try to manage fence installation by yourself, however, note some installation mistakes to avoid, so your fence is strong and secure, and so that you won't face unnecessary repairs once your fence is erected.
If you want to add a gate to the fence, you'll need to consider the slope of the driveway or walkway, and how that gate will open. If the gate hits a slope, it will get stuck and not open freely, so you may need to downsize the gate panels or choose a sliding gate. Note that there are usually special fence posts that are used for gates, versus those that anchor a fence into the ground. The added weight of gates typically requires a stronger and thicker post, so be sure you invest in the right posts if you'll be adding any type of gate to the fence.
Close to the ground
You might assume that a fence should sit level to the ground, perhaps even thinking that slats or panels should be nestled into the dirt, but this isn't always the case. Wood fences can absorb moisture from the ground, making the material more prone to rot and mould. Putting other fencing materials right on the ground can allow debris and even dirt to build up at the fence base. Very often, it's good to leave a few inches or centimetres between the fence and the ground, to avoid damage to the fence and this unsightly build-up.
Not planning for landscaping
If you have trees, shrubbery, or other landscaping features in your yard, you want to consider how to plan the fence around these features. Don't assume you can run a fence too close to mature trees or bushes or other such vegetation, as branches may brush up against the fence and cause it to lean, or cause it to absorb moisture and then rot or rust. You may also not like the look of shrubbery or other bushes getting flattened by a fence! Consider the proper clearance needed for such landscaping features, as well as flowerbeds, a vegetable garden and other features in your yard so you can plan the fence around them properly.